Package daikon.chicory

Class Instrument

Object

StackMapUtils

InstructionListUtils

Instrument

All Implemented Interfaces:

ClassFileTransformer

public class Instrument
extends InstructionListUtils
implements ClassFileTransformer

The Instrument class is responsible for modifying another class' bytecode. Specifically, its main task is to add "hooks" into the other class at method entries and exits for instrumentation purposes.

Field Summary

Fields

Modifier and Type	Field	Description
static SimpleLog	debug_transform	Debug information about which classes are transformed and why.

Fields inherited from class StackMapUtils

debugInstrument, firstLocalIndex, initialLocalsCount, initialTypeList, liveRangeEnd, liveRangeOperandSize, liveRangeStart, liveRangeType, needStackMap, numberActiveLocals, pool, runningOffset, smta, stackMapTable, stackTypes

Constructor Summary

Constructors

Constructor	Description
Instrument()	Create a new Instrument.

Method Summary

Modifier and Type	Method	Description
void	dump_code_attributes(MethodGen mg)
static boolean	shouldIgnore(String className, String methodName, String pptName)	Returns true if the given ppt should be ignored.
byte @Nullable []	transform(ClassLoader loader, @InternalForm String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer)	Given a class, return a transformed version of the class that contains "hooks" at method entries and exits.

Methods inherited from class InstructionListUtils

append_inst, build_il, calculateLiveLocalTypes, calculateLiveStackTypes, delete_instructions, insertAtMethodStart, insertBeforeHandle, replaceInstructions

Methods inherited from class StackMapUtils

addNewParameter, addString, adjust_code_for_locals_change, bcelCalcStackTypes, buildUninitializedNewMap, create_local_from_live_range, create_method_scope_local, createNewStackMapAttribute, findStackMapEqual, findStackMapIndexAfter, findStackMapIndexBefore, fixLocalVariableTable, gen_locals, gen_locals_from_byte_codes, gen_locals_from_byte_codes, generate_Type_from_StackMapType, generateStackMapTypeFromType, get_attribute_name, get_local_variable_type_table_attribute, getSize, getStackMapTable_attribute, is_local_variable_type_table, isStackMapTable, modifyStackMapsForSwitches, printStackMapTable, remove_local_variable_type_table, set_method_stackTypes, setCurrentStackMapTable, typeToClassGetName, update_full_frameStackMap_entries, updateStackMapOffset, updateUninitializedNewOffsets

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ClassFileTransformer

transform

Field Detail

debug_transform

public static SimpleLog debug_transform

Debug information about which classes are transformed and why.

Constructor Detail

Instrument

public Instrument()

Create a new Instrument. Sets up debug logging.

Method Detail

shouldIgnore

public static boolean shouldIgnore(String className,
                                   String methodName,
                                   String pptName)

Returns true if the given ppt should be ignored. Uses the patterns in Runtime.ppt_omit_pattern and Runtime.ppt_select_pattern. This method is used by both Chicory and Dyncomp.

Parameters:

className - class name to be checked

methodName - method name to be checked

pptName - ppt name to be checked

Returns:

true if the item should be filtered out

transform

public byte @Nullable [] transform(ClassLoader loader,
                                   @InternalForm String className,
                                   Class<?> classBeingRedefined,
                                   ProtectionDomain protectionDomain,
                                   byte[] classfileBuffer)
                            throws IllegalClassFormatException

Given a class, return a transformed version of the class that contains "hooks" at method entries and exits. Because Chicory is invoked as a javaagent, the transform method is called by the Java runtime each time a new class is loaded.

Specified by:

transform in interface ClassFileTransformer

Throws:

IllegalClassFormatException

dump_code_attributes

public void dump_code_attributes(MethodGen mg)